Ride a snow machine through icy tunnels near Anchorage.

"The blue ice is like nothing you’ve ever seen before," says Connie Cooley, co-owner of Glacier City Snowmobile Tours, which leads trips from Girdwood, Alaska, 40 miles southeast of Anchorage, to the aquamarine ice caves, tunnels, and slides at Spencer Glacier. “We had one formation a few years ago shaped like a big wave. People posed on it like they were surfing.”

Unless you come by ski, dogsled, or helicopter, the only way to reach the glacier during winter is by snow machine, a vehicle that provides its own thrills. Surrounded by the Chugach Mountains’ dramatic peaks, riders zoom over snow bridges and across the white expanse of the valley floor at 30 miles an hour.

The tour also slows down to marvel at frozen waterfalls and the otherworldly landscape along the way. “This is not about how fast or far you go,” Cooley says. “It’s about getting up close and personal with a glacier.” (907) 783-5566, snowtours.net.